.thumbnail{
position: relative;
z-index: 0;
}

.thumbnail:hover{
background-color: transparent;
z-index: 500;
}

.thumbnail span{
position: absolute ;
background-color: black;/*lightyellow*/
padding: 5px;
top: 100%;
left: -1000px;
border: 2px solid gray;
visibility: hidden;
color: #ffffff;
text-decoration: none;

}

.thumbnail span img{
border-width: 0;
padding: 2px;
}

.thumbnail:hover span{    
visibility: visible;
left: -200px;

}
